Aircraft currently use different subnetworks for air-to-air and air-to-ground communications in different phases of flight. The different subnetworks include very high frequency (VHF), high frequency (HF), and SATCOM networks. Main service providers for these subnetworks that allow communications between aircraft and aircraft/ground include ARINC and SITA.
With increasing air traffic, communication costs are also increasing for the airlines as the quantum of messages directly increases with the number of aircraft. Because of the high costs in using the subnetworks, communications are typically restricted to only the basic requirements, such as ACARS messaging and communications with air traffic control (ATC) or aeronautical operational control (AOC). With technology improvements, the demand for personal phone, facsimile, internet, and entertainment have also increased. If an airline does not meet such demands, the airline may lose business.
An airline pays a service provider for every message exchange of an aircraft, which is a substantial cost for the airlines. In a free flight scenario, communications play a major role in enhancing the safety of the flight, and thus many messages are required. Airlines thus have a need for technologies that will provide cost savings for communication services typically taken from service providers like ARINC and SITA.
The existing subnetworks have low bandwidth and limited speed capability to transfer multiple block downlinks to the ground. Because of technology constraints (e.g., speed, range), most aircraft perform much of their datalink activities on the ground. An aircraft typically uses expensive avionics equipment (mainly due to higher level certifications) to perform operations and provide information to the pilot to help in navigating through various terrain, in the approach to a runway, or at an airport during taxiing to the gate. This is especially required in bad weather where there is limited or no visibility.
Further, there may not be VHF coverage while flights are en route on the oceans, and pilots need to rely on HF or SATCOM. Unfortunately, SATCOM is the costliest form of communication, and HF works on ionospheric refraction, which does not provide much voice clarity and has frequent disconnects while transmitting data.
The frequency band of existing subnetworks (mainly VHF 118-136 MHz) remains congested. This becomes more complicated during take-off and landing phases where many ATC and AOC messages are exchanged. There is also no aircraft-to-aircraft communications available, either in en route or during different phases of flight, which allow for sharing data related to traffic, weather, etc.
Accordingly, there is a need for improved aircraft communication techniques that overcome the above deficiencies.